A great deal of research has been performed on the electrical properties of the phthalocyanines.
The results of this research are to be found, for example, in the following documents: (1) Japanese Pat. Nos. JP 047 295, JP 047 296, and JP 047 297, dated Mar. 9, 1985, (2) "Formation of MIS Structure in Organic Cell Al/Pb - Phthalocyanine/ITO" Kanayama et al - Japanese Journal of Applied Physics - Volume 22, No. 2, February 1983, pages 348-350, (3) "Phthalocyanineelectrolyte Schottky - junction devices" - Loufty et al - Can. J. Chem., Volume 61, 1983 - pages 72-77, (4) "Molecular material based junctions: Formation of a Schottky contact with metallophthalocyanine thin films doped by the cosublimation method" - Maitrat et al - J. Applied Physics, 60, Oct. 1, 1987, pages 2396-2400, (5) "Molecular semiconductors and junction formation: phthalocyanine derivatives," Andre et al - Synthetic Metals, 18 (1987), 683-688.
These documents show that in certain configurations and/or under certain doping conditions, phthalocyanines have semiconductor properties enabling devices to be made which act as diodes.
However, the phthalocyanine-based devices proposed heretofore are very unstable in air, as mentioned in the above-mentioned documents. Further, it has been very difficult in the past to obtain phthalocyanine-based films which are thin and uniform.
An object of the present invention is to eliminate the drawbacks of the prior art and to propose a structure suitable for defining a transistor type organic semiconductor device.